Pemanfaatan Ekstrak Kulit Ubi Ungu Sebagai Indikator Asam-Basa Alternatif Berupa Kertas Berdasarkan Pengaruh Variasi Jenis Pelarut Dan Jenis Kertas

The pH indicator existence is very important to support the mastery of certain material concepts that require practicum, especially on the material of Substances Classification in Science Learning of High School. Some species of plant can be used as alternative acid-base indicators because they contain anthocyanins. Purple sweet potato peel contains pigment which is flavonoid compound called anthocyanin. This research aims to know the effect of the drying temperature of the material and the type of solvent to the color changes produced on the acid-base indicator paper of the purple sweet potato peel extract after being tested. This research used experimental method with Completely Randomized Design (CRD) using two treatment factors they are types of paper variation (filter paper, HVS, paper opaque) and solvent type (ethanol 96% and ethanol 96%+ HCI 1%). The parameter in this research is the color change and pH of acid-base indicator paper from purple sweet potato peel extract after dipped into acid and base solvent. Based on the research result can be concluded that the best quality is shown by the acid-base indicator paper with filter paper and ethanol 96% solvent, because it is able to show more contrasting color degradation (bright pink color in strong acid, yellow in strong base, bright pink on weak acid, and green on a weak base)